I was always under the assumption to use a new head gasket, but the last time I re-used the old head gasket and had no issues. It was copper and a single cylinder air cooled two stroke. With water cooled, I would probably opt to get a new gasket. It all depends on how hard it is to replace later, if there is a issue.

Briggs always says you can reuse the gaskets if they don't come apart and I've done that without issue many times, but if there's any question about it or if you just want to follow best practices, get yourself a new one.

Briggs always says you can reuse the gaskets if they don't come apart and I've done that without issue many times, but if there's any question about it or if you just want to follow best practices, get yourself a new one.

No worries when recycling the head gasket, I'd run the same head gasket for a couple years when I built and raced 5hp WKA.

I do recall an old article about using a 'used' head gasket on british cycles that said to 'cook' the head gasket at 250° for 20 minutes, and then spray with a copper base spray made for gaskets.(time and temp are guesses)It was supposed to work but 'expanding' the gasket. The spray helped seal the surface.Newer gaskets are made different so I don't know it that would work anymore.

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There's no such thing as:Too big of a battery,Too large of a gas tank,or too loud of a horn,or too bright headlights.

Is this an OHV Kawi or an old flat head? With flat heads I would'nt sweat reusing the HG at all. If it's OHV where there's lots more steps to removing/replacing the head, I'd use a new gasket for sure.

Thanks. It's a flat head. This project is becoming more involved and costly than I had wanted it to. I'll reuse the old gasket for now, unless I can find one locally today. If I can get any compression at all I'll be ahead of where I was. It's relatively easy to go back later with a new gasket. I just want to see if I'm making progress or not. Probably time for the junk yard.

I do recall an old article about using a 'used' head gasket on british cycles that said to 'cook' the head gasket at 250° for 20 minutes, and then spray with a copper base spray made for gaskets.(time and temp are guesses)It was supposed to work but 'expanding' the gasket. The spray helped seal the surface.Newer gaskets are made different so I don't know it that would work anymore.

Good advice dw.

The heating process you've mentioned is known as annealing.

Definition: Heating steel to, and holding at a suitable temperature, followed by relatively slow cooling. The purpose of annealing may be to remove stresses, to soften the steel, to improve machinability, to improve cold working properties, to obtain a desired structure. The annealing process usually involves allowing the steel to cool slowly in the furnace.

Many people use this process to "recondition" copper head gaskets on vintage two cycle motorcycles. We generally use a butane/propane torch to heat the gasket then let it cool. If the gasket is not showing any signs of fracture, I'd anneal it and re-use it without hesitation.

Don't expect copper to "relax" the same way elastomers do. It'll only relax (instantaneously) as much as its elastic properties allow. Heat will not expand the metal. Heat just anneals the hardened metal so it can be further compressed without excessive strain hardening.